If you perform a lot of commuting and cover many miles each day, your automobile may eventually need realignment. You can test the timing for realignment by driving slowly, such as a roll-up to a stop sign, and slightly easing your grip on the steering wheel. If the car seems to instinctively pull one direction or another, then realignment may be in order.
You may also note this tendency when making a turn, and the car wants to go strongly in a certain direction as you pull the wheel. Other things to note while driving include knocking sounds from the vehicle. Turn off the radio and listen for any noises as you roll along. If there is a clattering or knocking noise, there may be a bolt loose in the undercarriage.
Alignment work will include inspection of items related to the issue. This could include a review of struts bearings and ball joints, bushings, and sway bar links. Catching issues early on can help save you costly repairs down the road, as suspension or alignment problems can become complex if left in disrepair. Simple issues such as driving through road construction zones day after day may actually lead to problems with the suspension.
These rough roads, where paving has been stripped, can put excessive strain on shocks and struts. Over time, even bolts near the tires may rattle loose. If you have not had your car examined lately, then even simple rumble strips on the side of the road might lead to problems with a car that needs work.
Things that a mechanic may look for are leaky or cracked shocks, amount of unnecessary vehicle motion such as bouncing or swaying, and tire wear that is not even. The tire issue, in particular, can mean that shocks and struts need replacement. Excessive bounce experienced in a vehicle can affect overall control of the car, comfort during riding, and even the ability to brake in a timely manner.